Show whole topic
Jun 27, 2011 4:46 pm
Jun 27, 2011 4:46 pm
Subject: Re: pistons etc. needed for M45 rebuild
Afternoon Barry,
We have pistons in stock, for bores, 3.5" 3.52" and 3.53" I do not recommend going larger than this!
These are "Forged" top quality low expansion silicone alloy pistons and are designed specifically for the Meadows engine by us.
The Volvo piston is a bit of a common problem as this piston is designed to be run "fully floating" ie. moving in the big end AND in the piston. the pistons are HIGH expansion ally and the pin is fitted a little tight in the piston so that when the piston expands, the pin is then the correct fit. The problem occurs when fitted with locked pins in the connecting rod, as in a standard Meadows, so that when cold the piston can not move freely on the pin, it then exerts excessive side load onto the rings and skirts and over heats the piston. The high expansion means the bores must be loose to start with and this also allows more piston "flop" as the piston goes from upwards thrust to downward thrust at tdc, Not very good but we all were thankful to Volvo when we had no other choice!
Running in was also crucial for at least 1500 miles at very gentle throttle loads!
Life is easier now thankfully ;o)
Best regards,
Julian
PS.
Barry,
There are no genuine "stupid Questions"
There are only ones we know the answer too or those we don't,
Unfortunately in our short lives, the latter are in a vast majority!
Afternoon Barry,
We have pistons in stock, for bores, 3.5" 3.52" and 3.53" I do not recommend going larger than this!
These are "Forged" top quality low expansion silicone alloy pistons and are designed specifically for the Meadows engine by us.
The Volvo piston is a bit of a common problem as this piston is designed to be run "fully floating" ie. moving in the big end AND in the piston. the pistons are HIGH expansion ally and the pin is fitted a little tight in the piston so that when the piston expands, the pin is then the correct fit. The problem occurs when fitted with locked pins in the connecting rod, as in a standard Meadows, so that when cold the piston can not move freely on the pin, it then exerts excessive side load onto the rings and skirts and over heats the piston. The high expansion means the bores must be loose to start with and this also allows more piston "flop" as the piston goes from upwards thrust to downward thrust at tdc, Not very good but we all were thankful to Volvo when we had no other choice!
Running in was also crucial for at least 1500 miles at very gentle throttle loads!
Life is easier now thankfully ;o)
Best regards,
Julian
PS.
Barry,
There are no genuine "stupid Questions"
There are only ones we know the answer too or those we don't,
Unfortunately in our short lives, the latter are in a vast majority!